Method for the production of cleaning devices



Nov. 5, 1963 A, PoLlTzER ETAL 3,109,703

METHOD FOR THE PRODUCTION OF' CLEANING DEVICES Filed Feb. 6. 1961 A J Fclean H- @m um 0 wn M um wm hm m.

3,109,703 METHOD FOR THE PRODUCTION OF CLEANING DEVICES Alfred Pulitzer, Cleveland, James Teng, Parma, Frank Pekarek, Cleveland, and Alvin B. Shockley, Berea, Ohio, assignors to Nylonge Corporation, Cleveland, Ohio, a corporation of Ohio Filed Feb. 6, 1961, Ser. No. 87,398 9 Claims. (Cl. 18-59) The present invention relates generally to an improved method for the production of cleaning and scouring devices and it relates more particularly to an improved method for the production of cleaning and scouring devices formed at least -in part of regenerated cellulose sponge and to the nnproved product resulting therefrom.

The conventional cleaning and scouring devices range in character from the relatively soft highly Water absorbent natural or synthetic sponge to the highly abrasive steel wool pads. These devices are particularly suited for certain limited uses but when employed for other purposes they possess numerous drawbacks and disadvantages and at best represent an unsatisfactory compromise. The sponge type device is characterized by being capable of retaining `and dispensing large quantities of water and detergent; solution but has a low abrasive quality. As a consequence, it is frequently necessary to employ a powdered abrasive or grit with the sponge, thus necessitating the subsequent -rinsing of the scoured surface and cleaning of the sponge to remove the powdered abrasive from the surface and sponge.

vIt has been proposed to incorporate a powdered abrasive in a synthetic sponge, but this is of little value since any abrasive that is available at the sponge surface is very shortly dissipated or masked. The common steel wool pad, on the other hand, while possessing suitable abrasive qualities, is of low water retention and rapidly deteriorates by reason of its rusting and physical disintegration. By substituting a rustproof material, such as bronze or ustainless steel for the steel wool, the rusting is eliminated but the other disadvantages remain while the cost is greatly increased. Soap impregnated steel pads are likewise shortalived and the soap rapidly dissipated. All have the draw-backs of being rough on hands, and fiber pads frequently prick the skin and cause festering sores. Sponges formed of foamed synthetic organic thermoplastic Inaterials have also been provided wtih abrasive carrying layers, but these too leave much to be desired.

It has been found that the drawbacks of the conventional cleaning and scouring devices are overcome and a highly improved product achieved by employing a regenerated cellulose sponge base upon a face of which is superimposed and secured a preferably abrasive carrying nonwoven thermoplastic liber pad or mat. There must be complete freedom of ow between the fibrous pad and the sponge member whereby the sponge member serves as a reservoir for a soap or detergent solution and the fibrous pad serves as a -suds reservoir and scouring surface, the sponge feeding the pad additional detergent solution only as needed. Many diiculties are encountered in fabricating a product of the above nature and characteristics. Where Ian adhesive is employed to effect the joining of the sponge member and the fibrous mat there results an undesirable impediment to the ow of liquid from the sponge to the fiber mat, an undesirable stifiening of the product occurs and the connection is often insecure. On the other hand, the securement of the fiber mat to the sponge member by embedding the sponge mat fibers in the sponge, per se, has not been satisfactorily achieved. The insufficient embedment of the fibers has resulted in the easy separation of the fiber mat from the sponge. On

United States Patent O ICC the other hand, it has been found that where the mat fibers are too deeply embedded in the sponge the resulting device is too stiff.

It is therefore a principal object of the present invention to provide an improved method for the production of cleaning and scouring devices.

Another object of the present invention is to provide an improved method for the production of cleaning and scouring devices formed at least in part of regenerated cellulose sponge.

Still another object of the present invention is to provide an improved method for securely laminating regenerated cellulose sponge and `a non-woven fibrous web without impeding the ilow of liquid between the sponge and fibrous web.

A further object of the present invention is to provide an improved method for the coagulation and regeneration of viscose masses.

Still a further object of the present invention is to provide an improved method of the above nature characterized by simplicity, low cost, versatility and flexibility.

The above and other objects of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawing, wherein:

FIGURE l is a top plan View of an apparatus embodying the present invention with which the subject improved 'process may be practiced;

FIGURE 2 is a vertical longitudinal sectional view thereof;

FIGURE 3 is an enlarged sectional view taken along line 3-3 in FIGURE 2; and

FIGURE 4 is a perspective view, of a scouring device produced in accordance with the present invention illustuated partially broken away.

In one sense the present invention contemplates the improved method of producing an artificial sponge having a non-woven fibrous pad adherent to a face thereof comprising depositing on a face of said fibrous mat a layer of a duid sponge 'forming mass under a pressure sufcient to effect the embedment of said face of said pad on said sponge forming mass, relieving said pressure and thereafter coagulating said sponge forming mass.

Another important feature of the present invention resides in the discovery that a viscose mass, for example, a viscose sponge forming mass, can be coagulated and regenerated in a superior manner and at a small fraction of the time consumed with the conventional methods by first passing an electric current through the viscose mass to heat the mass to a temperature suicient to effect the coagulation of the viscose but below the cellulose regeneration temperature and thereafter immersingl the coagulated viscose mass in a hot liquid bath at a temperature above the cellulose regeneration temperature. An important consequence of the above finding is that improved results may be achieved, particulanly by continuous processing, with a minimum of equipment at a relatively high production rate.

The improved apparatus with which the above process may be practiced to advantage includes an elongated trough adapted to contain a hot liquid and having a trailing feed end and a leading discharge end, an endless conveyor having an upper advancing run extending along the base of said trough and provided with a trailing section located above the level of said liquid, means for depositing a viscose sponge forming mass layer on said conveyor trailing section and electrodes connected to a source of current and extending along said conveyor trailing section in advance of said depositing means and adapted to contact the viscose sponge forming layer.

Referring now to the drawings which illustrate an ap- 3 paratus constitutingfa preferred embodiment of the present invention with which the present process can be practiced to produce the scouring device illustrated in FIG- URE 4 of the drawing the reference numeral 10 generalvly designates the improved scouring device which includes a regenerated cellulose base member 11 to a face of which is laminated a layer or mat l2` of a non-woven thermoplastic fibrous material which is advantageously of the type described in U.S. Patent No. 2,958,593, granted November 1, 1960, to H. L. Hoover et al., or other suitable non-woven thermoplastic fibrous mass. The fibers along the face of the layer 12 abutting the sponge member 11 penetrate the sponge member 11 between lt; and 1A inch and are firmly embedded therein to effect the tight adhesion between the sponge 11 and mat 12 without stiffening the device or impeding the fiow of liquid through the sponge-mat interface. The thicknesses of the sponge and the mat may be as desired depending on the end use.

The improved equipment is designated by the numeral 13 and includes a support frame comprising a pair of parallel transversely spaced longitudinally extending leg` supported upright channel members 14 to the undersides ,of which is suitably secured a bed plate 16 which is disposed below the level of the channel members 14. Resting on the bed plate 16 is a longitudinally extending trough 17 preferably formed of wood or other suitable electrically insulating and corrosion resistant material and including vertical side walls 18 and a main intermediate base or bottom wall 19 spaced above the bottom of the side walls 17 and the bed plate 16 and inclined slightly downwardly from its trailing to its leading end, that is from left to right as illustrated. The trough 17 terminates at its trailing end in a sharply forwardly downwardly inclined trailing section 20 and its leading end in a sharply forwardly upwardly inclined leading section 21. 1

The inner surfaces of the trough 17 are coated with a layer 25 of an electrical insulating corrosion resistant material such as rubber, the fluorinated olefins and the like, the layer 21 extending over the upper edges of the trough side walls 18. Positioned within the trough 17 along the side walls 1S and extending along the length of the trough between points on the trailing and leading sections thereof are a pair of electrode defining metal strips or plates 22. The strips 22 have parallel longitudinal edges and extend vertically from the bottom of the trough to a point short of the top thereof and are connected by suitable control means to the opposite poles of alternating current. Also disposed within the trough 17 is a deck or cover member 23, which extends from a point between the trailing end and mid point of the trough 17 through the leading lsection 21. The portion of the deck 23 coextensive with the main longitudinally extending trough base portion lies in a horizontal plane between the base 19 and the upper edge of the side walls 18.

Underlying the plate 16 and extending between the frame support legs is a longitudinally extending shelf 26. The shelf 26 is provided with upright flanges 27 along the side edges thereof and is supported by transverse straps secured to angle brackets fastened to the underface of the plate 16.

Suitably journalled between the frame channel members 14 adjacent their trailing ends and spaced a distance from the trough 17 is a first shaft 28 to which is affixed a first drum 29. Also journalled between the channel member 14 adjacent to their leading ends is a second shaft 32 to which is axed a second drum 33 which is of slightly less diameter than the first drum 29. A drive shaft 34 connected to a suitable drive motor and mounted on the channel member 14 by means of bearing brackets 36 extends between the shafts 28 and 32 and is coupled thereto by worm and gear drives 37 to drive the shafts 28 and 29 at the same angular speeds and the drum 29 at a greater peripheral speed than the drum 33.

The upper edgesof the drums 29 and 33 are at the level ofthe corresponding upper edges of the trough trailing and leading sections and a suitably supported plate 38 4 extends from the upper edge of the drum 29 to the trailing edge of the trough section 20. A flexible endless belt 39 is advanced by and supported by and between the drums 29 and 33 and includes an upper run advancing from the apparatus trailing end to the leading end thereof and a lower return run. The belt upper run extends from the drum 29 along the plate 38,V the base of the trough 17 including the trailing and leading sections 20 and 21 and to the drum 33. The belt return run is from the drum 33 along the shelf 26 and to the drum 29. In order to prevent the buckling of the belt 40 as it leaves the drum 29 a suitably mounted guide shield 41 is spaced about the drum upper trailingperiphery and then forwardly above the plate 38. To insure a positive non-slipping drive of the belt 40 by the drum 29 there is provided an idler roll 42 mounted on a horizontally hinged bracket 43 and resiliently swung thereby toward the drum 29 by a compression spring 44 to sandwich the belt 40 between the drum 29 and roll 42. f

A viscose mass containing reservoir or hopper 46 is disposed above the belt 39 and plate 38 immediately trailing the trough trailing edge and extends for substantially the width of the belt 39. The hopper 46 is open Y bottomed and includes vertical side walls 47 reaching the belt 39, an inclined rear wall 48 the lower edge of which is spaced a short distance above the belt 39 to permit the passage of the web which is to be'laminated and a vertical front wall 49 terminating at a point above the belt 39 t0 define an exit or extrusion slit 50, which may be adjustable in height and determines the thickness of the sponge layer superimposed on the fibrouskweb. Means are provided for feeding a viscose sponge forming mass V to the hopper 46 and maintaining the mass therein at a predetermined level.

A pair of transversely spaced uprights S1 are mounted at the trailing ends of the channel members 14 and terminate in rearwardly directed arms 52 which carry V-blocks 53. Supported by and 'between theV-blocks `53 is a shaft which carries a roll 54 of a non-woven thermoplastic web W of the type above described. A pivoted weighted arm 56 has its end resting on the roll 54 to retard the unrolling thereof. In order to guide the web W along the belt 39 under the hopper 46 a guide roller 57 is disposed directly behind the lower edge o-f the hopper rear wall 4S. j

Considering now the dimensions and operating parameters of the machine described above, the width of the trough and corresponding components may 4be as desired, for example about 20 to 40 inches, and the length of the trough +17 between the inner edges of the trailing and leading sections may be between about 6 and 15 feet, and the base thereof inclined between 3 and 8, preferably between 3 and 6 for example 4. 'Ilhe longitudinal dimension of the downwardly directed bottom opening of the hopper 46 is advantageously between 2 and 8 inches and preferably between 2 and 6 inches, for example 6 inches and the head of the mass V in the hopper is advantageously between 4 and .16 inches, preferably Ibetween 8 and 16 inches, `for example 10 inches. The rate of advance 'of the belt 39 is advantageously between 5 and l2 inches per minute, preferably in excess of 7 inches per minute, for example y8 inches per minute. The level of the regenerating liquid L in the trough 17 is such as to reach a point preferably |between the midpoint and the trailing edge of the trough and the deck 23 is at about the level of the liquid L and tenminates short ofthe edge of the liquid to permit the free passage of the transported viscose mass carrying web W which .it insures are completely immersed in the hot liquid L. The liquid L is advantageously a sodium sulphate solution of a concentration of between 15 and 28% by weight, preferably in excess 20%, for example 26% and may be in equilibrium with the sodiumy sulphate solution which is leached from the viscose sponge mass.l The temperature of the liquid L should be above the cellulose regeneration temperature and advantageously between 80 C. and 105 C., preferably in -excess of 90 C., for example 100 C. The liquid L may be heated by the electric current therethrough eiected by the electrodes 22, and may be additionally heated or fully heated by other suitable means i-n which latter case the electrodes 22 may terminate before reaching the liquid L. However, it is desirable, although not necessary, to pass electric current through the sponge forming mass while it traverses the liquid L. While it is desirable to apply the commercially available 11() volt A.C. voltage between the electrodes 22, the voltage may be varied but is advantageously between 80 volts and 300 volts and should be alternating. The current density through the viscose sponge mass in advantageously between 1 and 3 amperes per square inch, preferably less than 2 amperes, lfor example 1.2 amperes per square inch and before the sponge mass is immersed it should reach its coagulation temperature but advantageously not exceed 60 C.

The distance and time the viscose mass carrying web travels in engagement with the electrodes 22 prior to` immersion in the liquid L is advantageously 20 to 40 inches for 5 to 15 minutes, preferably 20 t0 30 inches for 5 `to minutes for example 30 inches -fo-r 6 minutes duration. The immersion time is advantageously 5 to 20 minutes, preferably 10 to 15 minutes for example 10 minutes and the distances traveled during immersion is advantageously 30 to 90 inches, preferably 40 to 80 inches, -for example 60 inches.

In practicing the presen-t process with the equipment described above in the production of the devices illustrated in FIGURE 4, a green viscose in produced in the conventional manner having a cellulose content between 7 and 10%, for example 8.0% an alkalinity between 5 and 7.5%, for example 5.6%, a total sulfur content of between 2.5% and 4.0%, for example 3.2% and a viscosity of 200500 seconds, for example 300 seconds as measured by the fall of a 1/4 inch diameter ball a distance of 8 inches. With 100i pounds of the above viscose there is adm-ixed 200 to 350 pounds of sodium sulphate decahydrate crystals yof a size between 40 mesh and 1/2 inch, for example 280 pounds of crystals 1/3 of which is 1A inch, 1/3 is 4 mesh and 1/3 is 10 mesh and l to 2.5 lbs. cut ax fibers, for example 1.6 pounds. The resulting viscose sponge forming mass, at a temperature advantageously between 10 C. and 21 C., preferably between C. and 20 C., for example 18 C. is introduced into the hopper 46 and the apparatus 13 operated in accordance with the conditions and parameters given above by way of specific example.

The 'web W is of the type described in the above identilied Hoover et al. patent yand may be any desired thickness, preferably between 1A?. inch and 1/2 inch, for example 14 inch and is fed onto the belt 39 under the roll 57 and beneath the hopper 46. A layer of the viscose sponge forming mass V of a thickness, for example, of inch is deposited on the traveling web W and penetrates the web W about 3/32 inch by reason of the pressure head on the mass V in :the hopper 46. It should be noted that the depth of penetration depends on the dimensions of the hopper opening, the pressure head on the mass V as well as the viscosity thereof and the rate of travel of the web W. Moreover in order to facilitate the penetration of the web W by the mass V, prior to the passage of the web W beneath the hopper 46 the upper surface thereof may be wetted with water, an aqueous solution of a surface active agent such as for example the alkyl sulfonates, the quaternary ammonium compounds, the sulfosuccinates, or with Ka dilute viscose or alkali solution. In addition, a rotatable embossing roll may rest on or be pressed into the upper surface of the viscose layer immediately upon emerging through the slit 50 to impress any `desired pattern therein, such as a waliied pattern. The embossing roll is preferably coated with a non-wetting material such as a fluorinated polyolefin and may,

if desired, be heated, to accelerate a skin formation on the viscose layer surface.

As the web carried viscose layer is transported between the electrodes 22 and before immersion thereof, it reaches a temperature of about 30 C. within about 4 minutes at which time the viscose is substantially completely coagulated and there is no significant regeneration of the cellulose. After passage through the heated liquid L the temperature of the sponge forming mass is raised above the cellulose regeneration temperature and almost complete regeneration is effected before it leaves the liquid L. The deck assures the immersion of the sponge mass in the liquid. In the -above example complete coagulation and regeneration is effected in about l5 minutes in contrast to the time of -45 minutes required according to conventional procedures. Following the trough 17 the laminated web and sponge may be washed, bleached, and plasticized or dried, or impregnated Withsoap or detergent and then cuit and packaged. v

While there have been described and illustrated preferred embodiments of the present invention it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof.

What is claimed is:

1. The improved method of producing a regenerated cellulose sponge having a non-woven thermoplastic fiber mat adherent to a face thereof comprising depositing on only one face of said fibrous mat in a substantially unimpeded state a layer of a sponge forming viscose mass under a pressure sufficient to effect the embedment of said mat face in said viscose mass for a fraction of the thickness of said mat and for only a fraction of the thickness of said layer and preventing the exposure of the other face of said mat to said sponge forming mass and the penetration of said mass thereto, relieving said pressure, coagulating said viscose and regenerating; the cellulose therein.

2. The improved method of producing a regenerated cellulose sponge having a non-woven thermoplastic fiber mat adherent to a face thereof comprising depositing on only one face of said fibrous mat in a substantially unimpeded state a layer of a viscose sponge forming mass having particulate sodium sulphate distributed therethrough for a fraction of the thickness of said mat under a pressure sufficient to effect the embedment of the face of said mat in said viscose a depth between V16 and 14a inch and for only a fraction of the thickness of said layer and preventing the exposure of the other face of said mat to said sponge forming mass and penetration of said mass thereto, relieving said pressure, coagulating said viscose and regenerating the cellulose therein.

3. The improved method of producing a regenerated cellulose sponge having a non-woven thermoplastic fiber web adherent to a face thereof comprising transporting said web in unimpeded form along a longitudinal path with only one face thereof in registry with a discharge opening of a reservoir containing a sponge forming viscose mass having particulate sodium sulphate distributed therethrough whereby to deposit a layer of said viscose mass upon only the confronting face of said web under sufficient pressure to effect the embedment of the fibers along said web face in said viscose mass for only a fraction of the thickness of said web, :and for a fraction of the thickness of said layer and preventing the exposure of the other face of said web to said sponge forming mass and penetration of said mass thereto, transporting said viscose mass carrying web beyond said reservoir opening and thereafter coagulating said viscose and regenerating the cellulose therein in the substantial absence of said pressure on said mass against said web.

4. The method according to claim 3 wherein the head on said viscose mass at said reservoir opening is sufficient to imbed said web face therein between 1/16 and i inch.

' posing only one face of said web while transported along part of said path to a fluid viscose sponge forming mass under pressure to effect only the partial penetration of said web by said Huid mass whereby the fibers of said web at the interface of said mass and said web are imbedded in said mass for only a fraction of the thickness of said mass and preventing the exposure of the other face of said web to said sponge forming mass and penetration of said mass thereto, and thereafter effecting the solidifcation of said sponge forming mass.

8. The Vmethod of producing :an artificial sponge having a permeable non-woven thermoplastic fiber web adherent to a face thereof comprising transporting said web in an unimpeded condition along a predetermined path and exposing only one face of said web while transported along part of said path to a fluid viscose sponge forrning mass having particulate sodium sulphate distributed therethrough under a pressure to effect only the partial penetration of said web by said uid mass whereby the fibers of said web at the interface of said mass and said web are imbedded in said mass for only a fraction of the thickness of said mass and preventing theV exposure of lthe other face of said web to said sponge forming mass and penetration of said mass thereto, and depositing a layer of said mass of predetermined thickness upon said web, relieving. said pressure and thereafter coagulating said mass.

9. The Imethod according to claim 8, wherein said pressure is such as to effect a penetration of between 1/16 and Ms inch.

References Cited in the le of this patent UNITED STATES PATENTS 1,117,604 Reid No'v. 17, 1914 1,528,537 Draemann Mar. 3, -1925 2,133,805 Brown Oct. 18, 1938 2,183,255 Czapek Dec. 12, 1939 2,313,125 Czapek Mar. 9, 1943 y2,371,155 Czapek Mar. 13, 1945 2,639,966 Stanton May 26, 1953 2,665,450 Lindquist Jan. 12, 1954 2,727,278 Thompson Dec. 20, 1955 2,786,790 Klein et al. Mar. 26, 1957 2,827,661 Y Von Kohorn Mar. 25, 1958 2,913,772 Buchkremer etal. Nov. 24, 1959 FOREIGN PATENTS 794,454 Great Britain May 7, 1958 

1. THE IMPROVED METHOD OF PRODUCING A REGENERATED CELLULOSE SPONGE HAVING A NON-WOVEN THERMOPLASTIC FIBER MAT ADHERENT TO A FACE THEREOF COMPRISING DEPOSITING ON ONLY ONE FACE OF SAID FIBROUS MAT IN A SUBSTANTIALLY UNIMPEDED STATE A LAYER OF A SPONGE FORMING VISCOSE MASS UNDER A PRESSURE SUFFICIENT TO EFFECT THE EMBEDMENT OF SAID MAT FACE IN SAID VISCOSE MASS FOR A FRACTION OF THE 